Electric cut-out



(No Model.)

W. J. JENKS. ELECTRIC GUT-OUT.

No. 437,362. Patented Sept. 30, 1890.

T Suva Hm QM I r C 334A dti'omw%' which an escape may at any time occur.

UNITED STATES PATENT OFFICE.

\VILLIAM J. JENKS, OF NYACK, NEW YORK.

ELECTRIC CUT-QUT.

SPECIFICATION formingpart of Letters Patent No. 437,362, dated September30, 1890.

Application filed June 16, 1890- Serial No. 355,669. (No model.)

To all whom it may concern.-

Be it known that I, l/VILLIAM J. J ENKS, a citizen of the United States,residing at Nyack, in the county of Rockland and State of New York, haveinvented an Improved Cut Out Apparatus for Electrical Instruments, ofwhich the following is a specification.

My invention relates to devices designed to protect electrical instrumen tssuch as telephone instruments, telegraph instruments, fire-alarminstruments, burglar-alarms, &c. and to protect the users thereof fromthe harmful efiects of high potential or other currents due to across-connection with other circuits or other causes.

The object of my invention is to produce an apparatus which shall cutout the instrument to be protected promptly and certainly, and thuslargely reducing the danger of burning out the instrument, or givingdangerous shocks to the user, or of setting fire to the building intowhich the circuit may extend.

It has been found that various devices, more especially when applied togrounded circuits, have to a certain extent protected the circuits andinstruments of the kinds mentioned against the heating effects ofcurrents of abnormal amperes; but serious difficulties have beenrealized in their application. In the effort to secure this protectionby means of fusible strips, for example, it has been found necessary tomake the strips so sensitive that they have been liable to accidentalrupture from mechanical or electrical causes. It also happens,especially in metallic circuits normally insulated from the earth andused for fire-alarm, telephone, and similar purposes, that, owing to across with an electric light or power conductor such metallic circuit israised to a high potential relative to the earth, or to some otherconduct-or with which there may be danger of contact, or to A circuitthus charged to a high potential may become a source of danger by itstendency to destroy the instruments connected with it, to

set fire to surrounding materials, or to give shocks to the user. Insuch acase there may be no flow of current from the insulated metalliccircuit, and therefore no device depending wholly upon the flow ofcurrent has proved sufficient under such conditions.

My present invention consists in providing a branch or shunt containinga potential circuit-controllersuch, for example, as described inmypatent, No. 428,564, dated May20, 1890between the instrument to beprotected and the line, with a magnet directly in the main line andoperating a shunting or circuit opening switch, and the combination withthe above devices of a fusible or thermal cutout, so adjusted as tooperate only on the passage of a current stronger than that required tooperate the magnet, and in other combina tions, as hereinafter describedand claimed.

The magnet being directly in the main line can be kept normally chargedto a partial extent, but not enough to attract its armature, by thecurrent on the line-as, for example, in closed-circuit fire -telegraphsystems-and can be made to operate its switch by a slight increase ofcurrent, thus making a more delicate apparatus than one in which theoperating-magnet is placed in a normallyopen ground branch. Thenecessary increase of current to operate the switch is immediatelyfurnished when the potential circuitcontroller is broken down, asdescribed in the above patent. If the dangerous rise in potential on thecircuit is of only short duration all that is necessary is to cut outthe instrument to protect it from injury. This is accomplished by thepotential circuit-closer. If. a current then flows of, say, one ampere,(which is too heavy for the telephone-coil,) the magnet will beenergized, thereby operating the switch to open the line or to form ashort circuit to earth.' In the latter case if the current increases,say, to two amperes, the fusible cut-out will be operated and sever theline. It sometimes happens also that the distance between the magnet andits armature gets too great by a disarrangement of the apparatus, or thearmature becomes locked by rust or some impediment, and in that case thefusible cut-out will operate irrespective of the magnet before thecurrent becomes of sufficient strength to destroy the potentialcircuit-closer.

In the accompanying drawings, which illustrate my invention, Figure 1 isa diagrammatic view of one embodiment of the invention in which theswitch operated by the magnet breaks the main line. Figs. 2 and 3 aremodifications in which the switch closes a short circuit.

In Fig. l the apparatus is shown-as applied to a groundedtelephone-line 1. 2 is the telephone apparatus. 3 is a branch or shuntleaving the line between the telephone and the line, said branchcontaining a potential circuit-closer 4. 5 is a magnet placed directlyin the main line on the line side of branch 3. The armature of thismagnet controlsa switch, which in this instance opens and leaves openthe main line, and the armature-leverforms a part of the switch. 6 is afusible cut-out in the line. The circuit-controller 4, which consists,preferably, of two plates very near together, preferably separated by aperforated disk of mica, and inclosed in an air-tight case, is adjustedto be operated or broken down on a definite rise of potential in thecircuit and before the magnet 5 is sufficiently energized to attract itsarmature. When the circuitcontroller is thus broken down alow-resistance path is formed to earth. If then a current of sufficientvolume to injure the tele phone flows over the line'the magnet willattract its armature and open the circuit. A cross is supposed to existat 11, between the telephone-circuit and another circuit carryingdangerous currents.

In Fig. 2 the invention is shown applied to a metallic circuit 1 1'. 2is the instrument to be protected, 3 3 branches or shunts from the linebetween the instrument and the magnets 5 5 which operates the switches,which are composed of the armature-levers and the springs 7 andco-operating contacts 8. The operation of this arrangement is asfollows: Upon a definite rise of potential the circuitcontroller 4allows the passage of current, thereby creating a low-resistance pathand shunting the instruments to be protected. Then if sufiicient currentflows over the line to earth the armature of magnet 5 or 5 is attracted,releasing spring 7, which snaps against contact 8, closing the shortcircuit to ground. If the current is momentary only, or is ofcomparatively low ampres-say, one ampre-the spring can at once bereplaced and the system will be in condition for use; but should aheavier current flow over the line the fusible cut-out 6 would be meltedand the line entirely opened at that point. If desired, a signal may beplaced at 9 to indicate the operation of the switch, and this signal maycontinue to operate until the fusible cut-out opens the line.

In Fig. 3 the armature of the switch-mag net is not normally in thecircuit, but when the armature is attracted the armature-lever snapsover the hook 10 and closes a short circuit to ground G, around both themagnet and circuitcontroller, as well as the telephone or otherinstruments. The operation of this modification will be cle ar-withoutfurther description.

It is evident that the location and form of some of the parts may bevaried to a considerable extent without departing from the invention.

In my application No. 340,703, filed February 17, 1890, I haveclaimed,broadly, the combination of a circuit, including an instrumentto be protected, a circuitopening device wholly in the main circuitbetween the line and instrument, a branch or shunt between thecircuit-opening device and instrument containingelectrically-disconnected circuit.-

terminals operated by a definite rise in potential before operation ofsaid circuit-open.- ing device, and also specifically the combination ofa circuit, including an instrument to be protected, a fusible cut-outwholly in the main circuit and between the line and instrument, a branchor shunt between the cut-out and instrument containingelectrically-disconnected circuit-terminals, and these combinations arenot claimed, broadly, in the pres ent application.

magnet directly in the main line for operating the same, and a branch orshunt between the instrument to be protected and the cally disconnectedcircuit terminals operative by a definite rise of'potential before theoperation of said switch-magnet, substantially as described.

2. The combination of a circuit, including an instrument to beprotected, a switch and an operating-magnet therefor, both directly inthe main line, a branch or shunt between the instrument and switchcontaining electrically-disconnected circuit-terminals operative on adefinite rise of potential before operation of said magnet, and a shortcircuit for the instrument closed by said switch, but

not including said terminals, substantially as 7 described.

roo circuit-opening device, containing 'electrir 3. The combination,with an instrument to be protected, a magnet in the main line, a branchor shunt between the instrument and line containing a potentialcircuit-closer 0perative on a definite rise in potential beforeoperation of the magnet, a short circuit closed by the magnet andmaintaining the circuit:

4. The combination, with an instrumentt be protected, of a switch in themain line, an

operating-magnet therefor, a branch or shunt between the instrument andline containing This specification signed and witnessed this a potentialcircuit-closer operative on a defi- 6th day of June, 1890. nite rise ofpotential before operation of the magnet, a short circuit closed by themagnet WILLIAM J. J ENKS. and containing an alarm, and a second cutoutfor completely severing theline on a fun Witnesses:

ther increase of current, substantially as de- CHARLES M. CATLIN,

scribed. SEIBERT SCHUOK.

